In a large bowl, sift flour, sugar, baking powder, and salt together. Separate egg whites and yolks into two separate bowls.
Beat egg whites until peaks form and set aside.
Add milk, oil, and vanilla to egg yolks and stir until just combined. Add wet ingredients to dry ingredients and mix well. Fold in egg whites.
Grease the waffle iron and preheat to medium-high. Add ½–⅔ cup batter per waffle to the iron and cook for 4–5 minutes, or until waffles are browned and crispy.
Serve warm topped with whipped cream, syrup, or your favorite fruits.